With respect to the solid electrolytic capacitor, Unexamined Japanese Patent Application Publication Nos. 6-151258 and 2004-18966 disclose a solid electrolyte capacitor having a manufacturing method including steps of anodizing an anode formed by valve metal, such as, aluminum, titanium, niobium and tantalum in the aqueous solution of phosphoric acid, forming a dielectric layer on the surface of the anode, providing an electrolytic layer structured by oxide having conductivity or conductive high polymer on the dielectric layer, taking out an anode terminal and a cathode terminal from capacitor element proving a carbon layer and a silver layer onto the electrolyte layer as the cathode terminal, and forming outer case by resin thereafter.
In recent years, the minimization and movement to large capacity of the solid electrolytic capacitor have been required. Instead of using conventional aluminum oxide and tantalum oxide as a dielectric, a solid electrolytic capacitor utilizing niobium oxide having a large dielectric constant has been proposed in Unexamined Japanese Patent Application Publication Nos. 2000-68157.
However, there has been a problem that a defective fraction becomes large due to the increase of leak current of final product on the manufacturing process of the conventional solid electrolytic capacitor as described above.